A liquid chromatograph analyzing device includes an analysis section comprising an automatic sampler, liquid sending pump, separation column and a detection device, and a computation section comprising, for example, a PC (personal computer). The computation section creates a chromatogram of a measured sample based on detection signals obtained by the detection device (see, for example, Patent Literature 1).
For example, with an analysis based on the temperature gradient method wherein the temperature of the mobile phase is changed with passage of time, because the baseline of the chromatogram drifts with the change in temperature of the mobile phase, background data for a chromatogram is obtained in advance by flowing a blank solution under the same conditions and measuring its chromatogram. As a correction process that is performed after a sample is measured, the background data can be subtracted from the chromatogram data that is obtained by measuring the sample, thus allowing the creation of a chromatogram that is free of the effects of baseline drift caused by a temperature gradient.    Patent Literature 1: Unexamined Patent Application Publication No. 2009-281897